Inclosed electric fuse.



F. N. GONANT.

INGLosBD ELECTRIC FUSE.

APPLICATION FILED PEB. 28,1910;

1,081,21 8. Ptendnee. 9, 1913.

wy. a, jmmr.' )4 mi MW t y llfz'nesscs:

UNITED STATES PATENT OFFICE.

l.FRANKLIN N. CONANT, OF NEWBURYPORT, MASSACHUSETTS,'ASSIGNOlR-TO CHASE; SHAWMUT COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION MAINE.

INCLOSED ELECTRIC FUSE. 'n'

Specification of Letters Patent.

Application led February 28, 191D. Serial No. 546,431.

To all whom t may concern:

Be it known that I, FRANKLIN N'. CONANT, of Newburyport, in the county of Essex `and State of Massachusetts, have invented an Improvement in Inclosed Electric Fuses, of which the following-is a specification. i

This invention relates-to ,inclosed electricfuses,.and particularly to improvements in the indicator which is employed for indieating when the fuse has blown.

Among the different types of fuse-indicators those having springs for actuating` them possess certain advantages over those actuated by explosives, in that they may be more cheaply manufactured and easily applied to the fuse.

This invention has for its object the production of a spring indicator having an isolated indicating plug adaptedto be expelled by pressure exerted upon it, an isolated actuating-spring therefor, adapted for self-expulsion when pressure upon it is relieved, both contained in a cylindrical case which is arranged in a hole in the Jfuse-case,

an 'indicator'controlling-wire and removable means connected -with .said wire for holding the actuating-spring compressed, which means also serves as a seat for local.- izing the indicating plug, whereby when the fuse blows and theA indicator controlling- 'wire is disrupted all of the parts contained in the-casewill be expelled.'

Another object of the invention is the provision of a disk having two holes through it, which is arranged above the isolated actuating-spring, 'and an indicator controlling- Wire made as a loop and-extended through the holes in said disk and through the spring which acts to hold said disk in p sition'tohold the actuating-spring compressed.

Figure 1 is a longitudinal section of an inclosed electric-fuse having a springindicator and means, embodying my invention, r for holdlnglits actuating-sprlng under tension. Fig 2 is-an enlarged sectional view of the spring-indicator. Fig. 3 is an eularged view of the spring-indicator as itleaves the fuse-case when the fuse blows Fig. 4 is a modification to be referred td.

` n, represents a fuse-case, and Z) a fusiblestrip connected .with the conducting-terminals Zi, of any usual or suitable form of in'closed electric-fuse. The fuse-strip has notches b2 at its sides atthe 'arc-forming point.

The spring-indicator here shown coniprises an indicating-plug c, preferably circular in form, contained in a hole c in the fuse-case and differing in color from the exterior of the fusefcase or label thereon, immediately surrounding said hole. When placed in the hole it occupies a position within the line of or outside surface of the wall of the fuse-case, and therefore is not liable to be rubbed oit' or injured in shipment. Said plug c is adapted to be, expelled by pressure exerted upon it, but it is not attached to its expelling-means, and hence is herein referred to as isolated.. A. disk c2 is located beneath the plug, which is arranged on or adapted to bear against the end of a spiral-spring c3, and said spiralspring is loosely` contained in, but is not attached to, a cylindrical flanged case c4, arranged in said hole in the fuse-case. The actuating-spring is therefore isolated. The actuating-spring is compressed by a pressure upon .the disk, which causes. a bodily movement of said disk, and,when the pressure is relieved, said-spring is caused to extend and by its react-ion against its support to bodily. yaway from-the case 0*, expelling the disk which hears uponV it and also 'the indieating-plug.- The case c* is preter- Patented Dec.9-, 1913.

The hole n in the fuse-ease is located quite remote from the arc-forming point of the fuse-strip, being therefore near one end of the fuse-case, so that, when the fuse bloyvs, there isa minimum danger of the vapors escaping through said hole, in which the indicator is placed. .I

A Wire d, of German silveror other s`uitahle material, or, infact, any other kind of wire, is looped .or otherwise4 attached to the disk c2, and is extended through the center. of the spring c? and through theu end Wall of the indicator-case 0*, and said Wire is then extended diagonally across the fusecase to a point near the opposite end thereof, as at rl', Where it. is attached to the fusecase by a plug, or other suitable means. prefer to have this Wire Il doubled, as 'it can be passed through tw'o holes in thev disk,

thus easily attaching the disk to it, and then y -the disk being expelled by the spring` and the spring being expelled by'the reaction against its support incident to its suddenly expanding when pressure upon it is relieved. -Furtherm'ore, said disk serves as a seat or limiting-stop for the indicating plug which localizes or determines the posi- Y tion of said plugin the cylindrical case and causes it, when compressed into the openin at the end of said case, to occupy a position in `the hole `in the case and'ush with the external surface thereof and to engage the edge -of said hole .all around its circumference instead of. having atendency to occupy angular positions withrespect thereto with a tendency to engage only portions of'the circumference and thus to fall outor by itsangular position to deceive the operator. Furthermore, the indicating plug can be placedA in position easily and quickly by an unskilled workman, dexterous. movement or manipulation is required for localizing it in the opening. 'It Ais simply placed into the opening against the seat and remains by 'frictional engagement with' the edge of the hole until expelled by the spring when pressure upon the spring 10 is relieved. Said wire crosses the fuse-strip and extends through one of the side notches formed therein at the arc-formingv point, and is therefore arranged in juxtaposition to said stri being partly on"one side and partly on t e other side thereof, and intersecting it at the arc-forming point. It will be observed that said wire is .not connected with the fuse-strip,'hence will not exert an appreciable strain thereupon, yet is in con- 50 tact with it until the fuse blows. When the fuse blows said wire d is immediatel ruptured and. the actuating-spring re eased, and, as before stated, said, spring` and disk and indicating-plug are all' immediately expelled from fuse-case.

In Fig.. ,4, the indicator-wire .is likewise made double and is carried through" two \holes in the disk c, but its strands are arranged one on each side of the fuse-strip, intersecting'it at the apc-,forming point.

.I claim:

1. In an inclosed electric-fuse, a' s ringindicator consisting of a cylindrica case having a anged head with a hole through '565 its head, said case being arranged in a hole wire 'extended through the hole in the head but it will' and means coextensive with the as no skill or in the fuse-case, an indicatinglug cntained in said case an'dlheld therein by frictional engagement therewith, `anactuating spring loosely contained in said case and unattached thereto, an indicator controllingof the case and through tlie actuating-spring, l area of the opening in-the case which is arranged y in the case beneath the indicating-plug an connected with said Vwire and which en a es the outer end of said spring and is he d y x said wire in position to hold the spring compressed, and which forms a seat for determining the position of the indicating-plug in the case, substantially as described. 2. In an inclosed electric-fuse,` a springindicator consisting of a cylindrical case having a flanged head with a` hole throughy its head, said case being arranged in a hole in the fuse-case, an actuating-spring loosely contained in said case and unattached thereto, a disk coextensive with the area of the 'i opening in the case which is arranged in the case above said spring, said disk havin@f two holes through it, an indicator controllingwire made as a loop which is extended through the 'holes' in said disk and through 'the spring and through the hole in the head of the case, its ends beino held fixed, said wire holding said disk with the actuatingspi-'ing compressed, and said disk adapted to beexpelled by the actuating-spring when pressure upon said spring is relieved, sub stantially las described.

3. In an inclosed electric-fuse, a" spring-- indicator consisting of a case, an indicatingplu contained. in said case'and held therein by rictional engagement therewith, 'an actuating-spring loosely contained in said case and. unattaclied thereto, an indicator controlling-Wire extended into the case, and means contained in the case and connected with one end of said wire and engaging said actuating-spring to hold said spring compressed, said means forming a seat for determining the position of the indicating-plug in the case lwithout exerting pressure thereupon while holding the actuating-spring compressed, substantially as described. L Y 4. In an inclosed electric-fuse, a springindicator having an indicating-plug held inj place by frictional engagement with its support, anactuating-s ring, an indicator con-v trolling-wire exten ed through Vthe actuat- 120 ing-springl and a disk connected with one end of said wire above said-spring and engaging said s ring to hold it compressed,

.said disk forming a seat for determining the v without ex- 125.

position of the indicating-plu erting pressure thereupon while holding the sprin compressed and adapted to be expelle by the spri of and to in turn expel the indicating-plug w en pressure upori the spring is relieved, substantially as described.

5. In an inclosedA' electlr-fuse, vaj springindicator havin@ an actuating-s ring, an indicator controlling-wire exten ed through -the spring, n disk arranged above the spring yand connected with one end of said Wire and engaging said spring to hold it compressed,

tance below the level of the fuse-case, and an indicating-plug tted 1nto the lspace above 10 said disk and held therein by frlction, said plng bearing uponsaid disk, whereby .its po sitio'n is determined by said disk, substantially as described.

In testimony whereof, I have signed m'y name to this specification, in the presence of 15 'two subscljibing witnesses. said disk being held by the wire a short ds` FRANKLIN N. CON ANT. lVitnesses:

B. J. Nouns, H. B. DA'vIs.

Copie: ot 11| patent may be obtained tor nve cents egch, by addressing the Commissioner o! hints.

Washington, D. C. 

